Figures and data

Two Price-like equations and two models.
In Model A, the number of offspring follows a binomial distribution with an expected number of offspring of α + β1pi. This means that the model can be summarized as wi = α + β1pi + εi (see Detailed Calculations A.6 at the end of the Appendices for details). For the transition depicted in panels a and c, we generated an offspring generation using Model A, with α = 1 and β1 = 1. Combining the Generalized Price equation in regression form with Model A includes choosing

Three rules and three models.
This table gives all combinations of the three rules and the three models discussed in the example. All rules indicate the direction of selection correctly for all models. Yellow indicates a combination of a rule and a model, where the rule is more general than is needed for the model. This leads to one or more b’s being 0. These are relatively harmless overspecifications. Red indicates a combination of a rule and a model, where the rule is not general enough (underspecified) for the model. This leads to b’s and c’s that depend on the population state. Terms that depend on the population state are abbreviated as follows: